Combustion device and method for operating a combustion device for low-nox and low-co combustion

Combustion device for a low NOx and low CO combustion with largely separated feeds of fuel and combustion air to a combustion chamber, wherein the entire or the largest part of the combustion air is fed to the combustion chamber in continuous gradation over numerous points in the chamber, characterized in that

• the combustion device comprises of a coaxial pipe, wherein the inner pipe (18) of the coaxial pipe joins in one or several feed lines (5) for the feed of combustion air in an area of an end of the coaxial pipe, and wherein the outer pipe (22) of the coaxial pipe joins at one or several feed lines (4) for the feed of fuel or, respectively, fuel-combustion air mixture in the area of said end of the coaxial pipe, and where a combustion-air distributor body (7) is sealingly connected with the inner pipe (18) of the coaxial pipe at the second end of the coaxial pipe, and wherein a nozzle row (12), including at least one or several fuel nozzles (13), sealingly closes the cylinder ring between the outer pipe and the inner pipe;
• the combustion-air distributor body (7) is made of an elongated inner hollow space, wherein the hollow space is surrounded by a thin, perforated or, respectively, porous wall, and wherein the combustion-air distributor body (7) includes a closed top part (9), an open bottom part (8), and a plurality of distributedly disposed openings (11) for the exiting of combustion air into the combustion zone;
• the combustion-air distributor body (7) is sealingly connected with its open bottom part (8) to the inner pipe (18) of the coaxial pipe;
• the length ratio (A/B) of the longitudinal extension of the combustion-air distributor body (7) relative to the longitudinal extension of the fire box (2) and the diameter ratio (C/D) of the cross-section of the combustion-air distributor body (7) at the bottom part (8) to the equivalent cross-section of the fire box (2) are dimensioned such that there results an ignitable mixture and that there starts a stable combustion;
• the fuel nozzles (13) are open on both sides and assure the feed of fuel or fuel-air mixture from the cylinder ring (21), enclosed between the inner pipe (18) and the outer pipe (22) of the coaxial pipe, into the combustion zone;
• the fuel nozzles (13) are disposed around the combustion-air distributor bodies in the region of the bottom parts (8) of the combustion-air distributor bodies (7);
• the jet flow direction (14) of the fuel nozzles within one and the same nozzle row (12) and/or the jet flow direction (14) of the fuel nozzles of neighboring nozzle rows (12) are separately settable;
• the combustion device is incorporated such into the fire box (2) that the end of the coaxial pipe with the feed lines for the combustion air and fuel feed (5) and (4) remains outside of the fire box (2), that the entire length of the combustion-air distributor body (7) is disposed in the fire box (2), and that the fuel nozzles (13) project into the fire box (2), however, do not surpass the distance of the bottom part (8) of the combustion-air distributor body (7) up to the start of the openings (11);
• one or several combustion devices are incorporated such into the fire box (2) that the combustion devices penetrate the outer wall (3) surrounding the fire box (2), and that the combustion devices have a sealing connection to the outer wall (3);
• the combustion zone in the fire box (2) is at the same time the zone for the complete mixing of the combustion air from the openings (11) with the fuel or, respectively, fuel-air mixture from the fuel nozzles (13);
• the volume and the geometry of the combustion zone corresponds essentially to the volume and geometry of that empty space (1) which is delimited by an outer wall (3), surrounding a fire box (2), wherein the outer wall exhibits the openings, in particular the incorporation of the combustion device and the exhaust gas exit (6), and delimited by the outer contour of one or several combustion-air distributor bodies (7), of which each body is disposed completely within the fire box (2), and delimited by an imaginary plane (10), disposed within the fire box (2) and sitting on the end of the top part (9) of the combustion-air distributor body (7).